Radiometer at a frequency of 108-120 GHz for study of the earth's atmosphere

Calculated and experimental design and operating characteristics of a 108-120 GHz superheterodyne radiometer with intermediate frequency modulation and a second harmonic frequency converter are presented and discussed. With a 1 sec time constant, the radiometer fluctuation sensitivity threshold is 1 K, without degradation in 2 hours of operation. Graphs of frequency variations, calibration, conversion loss, rectified current, fixed bias voltage, and contact needle impedance are included

Лёд 0 в природной среде. Экспериментальные данные и предполагаемые области его существования

The paper presents the available experimental data on ice 0 and the assumed objects of the cryosphere in which it can exist. This ice is formed from supercooled volumetric water, and it precedes the formation of ices Ih or Ic, at temperatures below −23 °C. This crystalline modification has been recently predicted by computer simulations using methods of molecular dynamics. Ice 0 was then experimentally found by electromagnetic investigation of wetted nanoporous media. Interest in this modification of ice was aroused due to its special physical and chemical characteristics. A singularity of ice 0 is that it is a ferroelectric that has a high static dielectric constant. When ferroelectric ice 0 contacts other dielectrics at their boundaries a thin layer is formed due to the diffusion of electric charges, and its electrical conductivity is higher than that of the contacting media. High electrical conductivity in thin films allows investigating frozen dispersed media containing ice 0 using non-contact electromagnetic measurement methods. As this takes place, it becomes possible to register water freezing processes in objects existing at temperatures of −23 ÷ −100 C using microwave spectroscopy and remote sensing methods. It is assumed that ice 0 is involved in chemical transformations in different objects of the cryosphere – in the atmosphere, and vegetation and soil covers. Its formation in the pores of materials of man-made structures may exert influence on the life-time of mechanisms and structures at low temperatures due to increased electrocorrosion. Ice 0 is assumed to exist on cold planets and their moons. That is why studying the possibility of ice 0 appearing in different objects of the natural environment at negative temperatures is so important for understanding their properties and developing remote sensing methods.Приводятся сведения о недавно открытом льде 0. Эта кристаллическая модификация образуется из переохлаждённой воды при температурах ниже −23 °С. Лёд 0, представляя собой сегнетоэлектрик, характеризуется особыми физико-химическими свойствами. Его существование возможно в поровом пространстве искусственных сооружений и природных сред на Земле, холодных планетах и их спутниках

Experimental evidence of the ferroelectric phase transition near the λ−\lambda-point in liquid water

We studied dielectric properties of nano-sized liquid water samples confined in polymerized silicates MCM-41 characterized by the porous sizes \sim 3-10nm. We report the direct measurements of the dielectric constant by the dielectric spectroscopy method at frequencies 25Hz-1MHz and demonstrate clear signatures of the second-order phase transition of ferroelectric nature at temperatures next to the \lambda- point in the bulk supercooled water. The presented results support the previously developed polar liquid phenomenology and hence establish its applicability to model actual phenomena in liquid water.Comment: 4 pages, single figur

Особенности структуры пропарины в ледяном покрове, образованной выходами газа

«Proparina» (russ) is a small hole in the ice cover formed by steaming of the ice by the gas vents. Some characteristics of this phenomenon were studied by the example of formation of one proparina found in March 2015 in the ice cover of the shallow eutrophic Lake Shakshinskoye (Trans-Baikal Region). The interest in this object is due to the fact that a proparina, unlike a polynya (small water opening in ice), is formed after the establishment of the ice cover and it can appear in those parts of a reservoir where there is no clearly expressed inflow or outflow of water. Although proparinas do often occur on some water bodies, e.g. Lake Baikal, a detailed description of their structure and process of formation is not available. Research on features of the proparina in the ice of the Lake Shakshinskoye and adjacent areas of this reservoir was carried out on March 25 and 28 in 2015. Melting at the lower and upper ice cover boundaries started at that time, and it was found that the proparina under investigation was formed in the center of a dome-shaped area where the ice thickness decreased compared to the adjoining parts within a distance of 200 meters. Gradient of the lower surface in the dome was on average 5 centimeters per 100 meters at a distance from the center. We found a narrow channel in the ice through which gas came into the proparina in the form of separate portions. The maximum recorded volume of gas that came into the open proparina reached 10 l/min. The channel is supposed to be formed at the end of winter period due to the release of gas during the melting of the lower layers of the ice cover and the subsequent movement of gas bubbles into the center of the dome. To study the ice cover structure, we measured thermo-microwave self-radiation of the “ice-water” system in the centimeter range. Such measurements allow detecting changes in ice thickness with an accuracy of 1 cm. It is assumed that the accumulation of gases under the ice causes the instability of the water column due to warming by the heat fl w from the bottom layers and initiates the circulation and, thus, formation of proparina.В ледяном покрове пресного озера Шакшинское (Забайкальский край) изучена пропарина, которая образуется после установления ледяного покрова и появляется в тех частях водоёма, где отсутствуют выраженные приток и сток вод. Пропарина размером 2 × 3 м2 сформировалась в вершине ледяного купола диаметром около 400 м. Обнаружен узкий канал, по которому в пропарину поступал газ, выделяющийся при таянии нижних слоёв ледяного покрова. Предполагается, что локальное накопление газов нарушает устойчивость столба воды из-за его разогрева потоком тепла из донных слоёв, приводит к возникновению циркуляции и образованию пропарины

Ice 0 in the natural environment. Experimental data and assumed areas of its existence

The paper presents the available experimental data on ice 0 and the assumed objects of the cryosphere in which it can exist. This ice is formed from supercooled volumetric water, and it precedes the formation of ices Ih or Ic, at temperatures below −23 °C. This crystalline modification has been recently predicted by computer simulations using methods of molecular dynamics. Ice 0 was then experimentally found by electromagnetic investigation of wetted nanoporous media. Interest in this modification of ice was aroused due to its special physical and chemical characteristics. A singularity of ice 0 is that it is a ferroelectric that has a high static dielectric constant. When ferroelectric ice 0 contacts other dielectrics at their boundaries a thin layer is formed due to the diffusion of electric charges, and its electrical conductivity is higher than that of the contacting media. High electrical conductivity in thin films allows investigating frozen dispersed media containing ice 0 using non-contact electromagnetic measurement methods. As this takes place, it becomes possible to register water freezing processes in objects existing at temperatures of −23 ÷ −100 C using microwave spectroscopy and remote sensing methods. It is assumed that ice 0 is involved in chemical transformations in different objects of the cryosphere – in the atmosphere, and vegetation and soil covers. Its formation in the pores of materials of man-made structures may exert influence on the life-time of mechanisms and structures at low temperatures due to increased electrocorrosion. Ice 0 is assumed to exist on cold planets and their moons. That is why studying the possibility of ice 0 appearing in different objects of the natural environment at negative temperatures is so important for understanding their properties and developing remote sensing methods